Apollo 12


Apollo 12 was the sixth crewed flight in the United States Apollo program and the second to land on the Moon. It was launched on November 14, 1969, from the Kennedy Space Center, Florida, four months after Apollo 11. Commander Charles "Pete" Conrad and Apollo Lunar Module Pilot Alan L. Bean performed just over one day and seven hours of lunar surface activity while Command Module Pilot Richard F. Gordon remained in lunar orbit. The landing site for the mission was located in the southeastern portion of the Ocean of Storms.
On November 19 Conrad and Bean achieved a precise landing at their expected location within walking distance of the site of the Surveyor 3 robotic probe, which had landed on April 20, 1967. They carried the first color television camera to the lunar surface on an Apollo flight, but transmission was lost after Bean accidentally pointed the camera at the Sun and the camera's sensor was destroyed. On one of two moonwalks they visited Surveyor 3 and removed some parts for return to Earth.
Lunar Module Intrepid lifted off from the Moon on November 20 and docked with the command module, which then, after completing its 45th lunar orbit, traveled back to Earth. The Apollo 12 mission ended on November 24 with a successful splashdown.

Crew

Commander Pete Conrad flew on Gemini 5 in 1965, and as command pilot on Gemini 11 in 1966. Command Module Pilot Richard F. Gordon Jr. flew with Conrad on Gemini 11. Originally, Conrad's Lunar Module pilot was Clifton C. Williams Jr., who was killed in October 1967 when the T-38 he was flying crashed near Tallahassee. When forming his crew, Conrad had wanted Alan L. Bean, a former student of his at the United States Naval Test Pilot School at Patuxent River NAS, Maryland, but had been told by Director of Flight Crew Operations Deke Slayton that Bean was unavailable due to an assignment to the Apollo Applications Program. After Williams's death, Conrad asked for Bean again, and this time Slayton yielded.

Backup crew

Support crew

EVA 1 start: November 19, 1969, 11:32:35 UTC

Launch and transfer

Apollo 12 launched on schedule from Kennedy Space Center, under completely overcast rainy skies, encountering wind speeds of during ascent, the highest of any Apollo mission.
Lightning struck the Saturn V 36.5 seconds after lift-off, triggered by the vehicle itself, discharging down to the Earth through the ionized exhaust plume. Protective circuits on the fuel cells in the service module detected overloads and took all three fuel cells offline, along with much of the command and service module instrumentation. A second strike at 52 seconds knocked out the "8-ball" attitude indicator. The telemetry stream at Mission Control was garbled. However, the Saturn V continued to fly normally; the strikes had not affected the Saturn V instrument unit guidance system, which functions independently from the CSM.
The loss of all three fuel cells put the CSM entirely on batteries, which were unable to maintain normal 75-ampere launch loads on the 28-volt DC bus. One of the AC inverters dropped offline. These power supply problems lit nearly every warning light on the control panel and caused much of the instrumentation to malfunction.
Electrical, Environmental and Consumables Manager John Aaron remembered the telemetry failure pattern from an earlier test when a power supply malfunctioned in the CSM signal conditioning electronics, which converted raw signals from instrumentation to standard voltages for the spacecraft instrument displays and telemetry encoders.
Aaron made a call, "Flight, EECOM. Try SCE to Aux", which switched the SCE to a backup power supply. The switch was fairly obscure, and neither Flight Director Gerald Griffin, CAPCOM Gerald Carr, nor Mission Commander Pete Conrad immediately recognized it. Lunar Module Pilot Alan Bean, flying in the right seat as the spacecraft systems engineer, remembered the SCE switch from a training incident a year earlier when the same failure had been simulated. Aaron's quick thinking and Bean's memory saved what could have been an aborted mission, and earned Aaron the reputation of a "steely-eyed missile man". Bean put the fuel cells back on line, and with telemetry restored, the launch continued successfully. Once in Earth parking orbit, the crew carefully checked out their spacecraft before re-igniting the S-IVB third stage for trans-lunar injection. The lightning strikes had caused no serious permanent damage.
Initially, it was feared that the lightning strike could have caused the explosive bolts that open the Command Module's parachute compartment to fire prematurely, rendering the parachutes useless which would have made safe return impossible. The decision was made not to share this with the astronauts since there was little that could be done to verify or resolve the problem if it existed. The parachutes deployed and functioned normally at the end of the mission.
After LM separation, the S-IVB was intended to fly into solar orbit. The S-IVB auxiliary propulsion system was fired, and the remaining propellants vented to slow it down to fly past the Moon's trailing edge. The Moon's gravity would then slingshot the stage into solar orbit. However, a small error in the state vector in the Saturn's guidance system caused the S-IVB to fly past the Moon at too high an altitude to achieve Earth escape velocity. It remained in a semi-stable Earth orbit after passing the Moon on November 18, 1969. It finally escaped Earth orbit in 1971 but was briefly recaptured in Earth orbit 31 years later. It was discovered by amateur astronomer Bill Yeung who gave it the temporary designation J002E3 before it was determined to be an artificial object.

Moon landing

The Apollo 12 mission landed on November 19, 1969, on an area of the Ocean of Storms that had been visited earlier by several robotic missions. The International Astronomical Union, recognizing this, christened this region Mare Cognitum . The Lunar coordinates of the landing site were 3.01239° S latitude, 23.42157° W longitude. The landing site would thereafter be listed as Statio Cognitum on lunar maps. Conrad and Bean did not formally name their landing site, though Conrad nicknamed the intended touchdown area "Pete's Parking Lot".
The second lunar landing was an exercise in precision targeting, which would be needed for future Apollo missions. Most of the descent was automatic, with manual control assumed by Conrad during the final few hundred feet of descent. Unlike Apollo 11, where Neil Armstrong had to use the manual control to direct his lander downrange of the computer's target, which was strewn with boulders, Apollo 12 succeeded in landing at its intended target—within walking distance of the Surveyor 3 probe, which had landed on the Moon in April 1967. This is the first and thus far only occasion in which humans have revisited a probe sent to land on another world.
Conrad actually landed Intrepid short of "Pete's Parking Lot", because it looked rougher during final approach than anticipated, and was a little under from Surveyor3, a distance that was chosen to eliminate the possibility of lunar dust from covering Surveyor3. But the actual touchdown point—approximately from Surveyor3—did cause high velocity sandblasting of the probe. It was later determined that the sandblasting removed more dust than it delivered onto the Surveyor, because the probe was covered by a thin layer that gave it a tan hue as observed by the astronauts, and every portion of the surface exposed to the direct sandblasting was lightened back toward the original white color through the removal of lunar dust.

EVAs

When Conrad, who was somewhat shorter than Neil Armstrong, stepped onto the lunar surface, his first words were "Whoopie! Man, that may have been a small one for Neil, but that's a long one for me." This was not an off-the-cuff remark: Conrad had made a bet with reporter Oriana Fallaci he would say these words, after she had queried whether NASA had instructed Neil Armstrong what to say as he stepped onto the Moon. Conrad later said he was never able to collect the money.
To improve the quality of television pictures from the Moon, a color camera was carried on Apollo 12. Unfortunately, when Bean carried the camera to the place near the LM where it was to be set up, he inadvertently pointed it directly into the Sun, destroying the Secondary Electron Conduction tube. Television coverage of this mission was thus terminated almost immediately.
Apollo 12 successfully landed within walking distance of the Surveyor 3 probe. Conrad and Bean removed pieces of the probe to be taken back to Earth for analysis. It is claimed that the common bacterium Streptococcus mitis was found to have accidentally contaminated the spacecraft's camera prior to launch and survived dormant in this harsh environment for two and a half years. However, this finding has since been disputed: see Reports of Streptococcus mitis on the Moon.
Astronauts Conrad and Bean also collected rocks and set up equipment that took measurements of the Moon's seismicity, solar wind flux and magnetic field, and relayed the measurements to Earth. The instruments were part of the first complete nuclear-powered ALSEP station set up by astronauts on the Moon to relay long-term data from the lunar surface. The instruments on Apollo 11 were not as extensive or designed to operate long term. The astronauts also took photographs, although by accident Bean left several rolls of exposed film on the lunar surface. Meanwhile, Gordon, on board the Yankee Clipper in lunar orbit, took multi-spectral photographs of the surface.
The lunar plaque attached to the descent stage of Intrepid is unique in that unlike the other plaques, it did not have a depiction of the Earth, and it was textured differently: The other plaques had black lettering on polished stainless steel while the Apollo 12 plaque had the lettering in polished stainless steel while the background was brushed flat.

Return

Intrepid's ascent stage was dropped after Conrad and Bean rejoined Gordon in orbit. It impacted the Moon on November 20, 1969, at. The seismometers the astronauts had left on the lunar surface registered the vibrations for more than an hour.
The crew stayed an extra day in lunar orbit taking photographs, for a total lunar surface stay of 31 and a half hours and a total time in lunar orbit of eighty-nine hours.
On the return flight to Earth after leaving lunar orbit, the crew of Apollo 12 witnessed a solar eclipse, though this one was of the Earth eclipsing the Sun.

Splashdown

Yankee Clipper returned to Earth on November 24, 1969, at 20:58 UTC, in the Pacific Ocean, approximately 500 nautical miles east of American Samoa. During splashdown, a 16 mm film camera dislodged from storage and struck Bean in the forehead, rendering him briefly unconscious. He suffered a mild concussion and needed six stitches. After recovery by, they were flown to Pago Pago International Airport in Tafuna for a reception, before being flown on a C-141 cargo plane to Honolulu.

Stunts and mementos

The Apollo 12 mission patch shows the crew's navy background; all three astronauts at the time of the mission were U.S. Navy commanders. It features a clipper ship arriving at the Moon, representing the CM Yankee Clipper. The ship trails fire, and flies the flag of the United States. The mission name APOLLO XII and the crew names are on a wide gold border, with a small blue trim. Blue and gold are traditional U.S. Navy colors. The patch has four stars on it – one each for the three astronauts who flew the mission and one for Clifton Williams, a U.S. Marine Corps aviator and astronaut who was killed on October 5, 1967, after a mechanical failure caused the controls of his T-38 trainer to stop responding, resulting in a crash. He trained with Conrad and Gordon as part of the backup crew for what would be the Apollo 9 mission, and would have been assigned as lunar module pilot for Apollo 12.

Spacecraft location

The Apollo 12 command module Yankee Clipper is on display at the Virginia Air and Space Center in Hampton, Virginia.
In 2002, astronomers thought they might have discovered another moon orbiting Earth, which they designated J002E3, that turned out to be the S-IVB third stage of the Apollo 12 SaturnV rocket.
The Lunar Module Intrepid impacted the Moon November 20, 1969, at 22:17:17.7 UT . In 2009, the Lunar Reconnaissance Orbiter photographed the Apollo 12 landing site. The Intrepid lunar module descent stage, experiment package, Surveyor3 spacecraft, and astronaut footpaths are all visible. In 2011, the LRO returned to the landing site at a lower altitude to take higher resolution photographs.

Orbital leftovers

The Apollo 12 third stage, an S-IVB, after passing the Moon on 18 November 1969 and not entering a Lunar orbit like the Command Module and Lunar Lander, entered an elliptical Earth orbit with a period of approximately 43 days, and thus became a derelict satellite orbiting Earth. Some time later, the spent third stage entered a heliocentric orbit, but was not observed doing so. The likely mechanism was via one of the Sun-Earth Lagrangian points, which serve "as a 'portal' between the regions of space gravitationally controlled by the Earth and Sun."
Notably, in April 2002, it reentered a temporary orbit around the Earth-Moon system near the Sun-Earth L1 Lagrangian point—"a location where the gravity of the Earth and Sun approximately cancel"—and remained in orbital synchrony with both the Moon and the Earth for a little over a year, reentering a heliocentric orbit in May 2003. The object was "discovered" by near-Earth object watcher Bill Yeung on 3September 2002, labeled object "J002E3" by the Minor Planet Center, and was subsequently identified as the former Apollo 12 stage only several days later. The rocket stage is "the first known case of an object being captured by the Earth, although Jupiter has been known to capture comets via the same mechanism."

Depiction in media

Portions of the Apollo 12 mission are dramatized in the 1998 miniseries From the Earth to the Moon episode entitled "That's All There Is." Conrad, Gordon, and Bean were portrayed by Paul McCrane, Tom Verica, and Dave Foley, respectively. Conrad had been portrayed by a different actor, Peter Scolari, in the first episode.